胰岛素对糖尿病大鼠肾小球蛋白激酶C表达的调控

THE EFFECT OF INSULIN ON THE EXPRESSION OF PROTEIN KINASE C IN DIABETIC RAT GLOMERULUS

目的 :探讨胰岛素对糖尿病 (DM)大鼠不同阶段肾小球蛋白激酶C(PKC)同工酶表达变化的影响。方法 :将实验动物随机分为正常对照组、STZ -DM模型组、胰岛素治疗组 2周、4周 ,采用免疫组化方法检测PKC同工酶的表达变化情况。结果 :胰岛素明显抑制了 2周、4周组DM大鼠肾小球PKCα的表达以及 4周组DM大鼠PKCβⅡ 的表达 ;PKCβⅠ 、ε表达无明显变化。结论 :胰岛素对DM大鼠不同阶段肾小球PKC各同工酶表达变化的影响不同。胰岛素治疗可以延缓糖尿病肾病 (DN)的发生、发展。

Objective: To investigate the effect of insulin on the expression of protein kinase C isoforms in diabetic rat glomerulus and evaluate the influence of insulin on the development of diabetic nephropathy.Methods:The animals were divided into control groups,diabetic groups and insulin treatment groups at random.Hyperglycemia was induced by streptozotocin (STZ,60mg/kg) in the male Sprague-Dawley rats (body weight 150～170g).Diabetes was confirmed by blood glucose ≥13.9mmol/L two day after STZ administration.Age-matched normal rats received the same amount of normal saline were served as a control group.Insulin is injected subcutaneously to control blood glucose below 11.1mmol/L at the daily dosage of 8～40.2 weeks and 4 weeks after the onset of hyperglycemia and treatment by insulin the expression of glomerular PKC isoforms in normal?diabetic and insulintreated groups was assessed by immunohistochemistry. Results:The expression of PKCa in Diabetic glomerulus 2 weeks, 4 weeks after insulin treatment showed a significant decrease. The expression of PKCβ Ⅱ 4 weeks after treatment also markedly decreased. While PKC β Ⅰ and PKC ε were not significantly changed after treatment.Conclusion:The effect of insulin on the expression of glomerular PKC isoforms in different stage of diabetic nephropathy are different. The treatment of insulin can delay the occurrence and development of diabetic nephropathy.